find the handoffs - eliminate them

find_handoff_parts.py

import sys
import os
import errno
from argparse import ArgumentParser
from collections import defaultdict

from swift.common.storage_policy import split_policy_string
from swift.obj.diskfile import get_data_dir
from swift.common.ring import Ring

parser = ArgumentParser()
parser.add_argument('-v', '--verbose', help='line oriented output',
                    default=False, action='store_true')
parser.add_argument('ring', help='specify the ring, infers datadir')
parser.add_argument('devices', help='root of devices tree for node',
                    nargs='?', default='/srv/node')
parser.add_argument('--limit', help='max number of handoff parts to output',
                    default=None, type=int)
parser.add_argument('--workers-per-device', type=int, default=1,
                    help='Number of output lines per device, '
                    'parts are split up evenly')


def split(seq, n):
    """
    split seq into n pieices
    """
    seq = list(seq)
    for i in range(n):
        yield seq[i::n]


def get_ring_and_datadir(path):
    """
    :param path: path to ring

    :returns: a tuple, (ring, datadir)
    """
    ring_name = os.path.basename(path).split('.')[0]
    base, policy = split_policy_string(ring_name)
    if base == 'object':
        datadir = get_data_dir(policy)
    else:
        datadir = base + 's'
    return Ring(path), datadir


def main():
    args = parser.parse_args()
    device_root = args.devices

    ring, datadir = get_ring_and_datadir(args.ring)
    dev2parts = defaultdict(set)
    for replica, part2dev in enumerate(ring._replica2part2dev_id):
        for part, device_id in enumerate(part2dev):
            dev2parts[ring.devs[device_id]['device']].add(part)

    # print dev2parts
    handoffs = defaultdict(set)
    device_dirs = os.listdir(device_root)
    for device_dir in device_dirs:
        parts_dir = os.path.join(device_root, device_dir, datadir)
        try:
            parts = os.listdir(parts_dir)
        except OSError as e:
            if e.errno == errno.ENOENT:
                continue
            else:
                raise
        for part in parts:
            if not part.isdigit():
                continue
            part = int(part)
            if part in dev2parts[device_dir]:
                continue
            handoffs[device_dir].add(part)

    for device, parts in handoffs.items():
        if args.limit is not None:
            parts = list(parts)[:args.limit]
        if args.verbose:
            # maybe verbose is more like --debug?
            print os.path.join(device_root, device)
            for part in parts:
                print '   ', part
            continue
        for sub_parts in split(parts, args.workers_per_device):
            print '-d %s -p %s' % (device, ','.join(str(p) for p in sub_parts))


if __name__ == "__main__":
    sys.exit(main())

push_handoffs.sh

#!/bin/bash
# WORKERS=4 push_handoffs.sh /etc/swift/object-1.ring.gz $(which swift-object-reconstructor) /etc/swift/object-server/1.conf.d
RING=${1:-/etc/swift/container.ring.gz}
CMD=${2:-/opt/ss/bin/swift-container-replicator}
CONF=${3:-/etc/swift/container-server/2.conf}
SCRIPT=find_handoff_parts.py
DEVICES=${DEVICES:-/srv/node}
PYTHON=${PYTHON:-/opt/ss/bin/python}
WORKERS=${WORKERS:-2}
set -xe
while true; do
	$PYTHON $SCRIPT --workers-per-device $WORKERS $RING $DEVICES > handoff_parts.log
	while read line; do
		$PYTHON $CMD $CONF -o -v $line &
	done < handoff_parts.log
	wait
    sleep 0.1
done